In a mass extinction event some 40,000 years ago, Australia lost 90% of its large species, including nearly two dozen kinds of kangaroos. Two theories suggest why.

Chile is set to gain its 47th national park early this year — largely due to the efforts of U.S. conservationist Kristine Tompkins and her organization.

Potential rooftop solar customers and installers worry the incoming Trump administration might try to eliminate a 30% federal tax credit. Some customers plan to install sooner because of that. And solar companies are changing their business plans.

The BepiColombo spacecraft flew less than 200 miles from Mercury's surface and photographed volcanic plains and icy craters.

The official numbers are in: 2024 is the hottest year on record. Climate change is the main culprit. But there might be something else going on, too.

As fire crews and air tankers work to block the wildfires' explosive growth, images of red clouds of fire retardant falling onto trees are common. What is it — and what's in it?

Southern states don't often deal with winter conditions, but New England does. New Hampshire especially has tips for how to prepare for a winter storm.

A new study on mice shows that luck in early life can determine success as an adult, especially when competition is high.

New Glenn, developed by the private space firm founded by billionaire Jeff Bezos, is on the pad at Cape Canaveral, Fla., and could launch on its maiden flight as early as Friday.

NASA has announced it is moving forward with several plans to return rock samples from Mars.